In the diagram below, AB is the chord of a circle with centre O. OM is perpendicular to AB (meet at a right angle). Look at triangles OAM and OBM. The hypotenuses (OA and OB) are the same, as they are ...
Two lines have equations \(y = {m_1}x + 3\) and \(y = {m_2}x - 7\). If the lines are parallel then \({m_1} = {m_2}\) and if \({m_1} = {m_2}\) then the lines are ...